Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/38—Polymers
  • C09K19/3804—Polymers with mesogenic groups in the main chain
  • C09K19/3809—Polyesters; Polyester derivatives, e.g. polyamides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/13—Phenols; Phenolates
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
  • C08L61/02—Condensation polymers of aldehydes or ketones only
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
  • C08L67/03—Polyesters derived from dicarboxylic acids and dihydroxy compounds the dicarboxylic acids and dihydroxy compounds having the carboxyl- and the hydroxy groups directly linked to aromatic rings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L71/00—Compositions of polyethers obtained by reactions forming an ether link in the main chain; Compositions of derivatives of such polymers
  • C08L71/08—Polyethers derived from hydroxy compounds or from their metallic derivatives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers

Definitions

• tracking is a phenomenon associated with the formation of permanent and progressive conducting paths on the surface of materials, usually by the combined effects of an electrical field and external surface pollution. Electrical tracking can occur when a damaged energized electrical part becomes wet, such as from electrolytes or condensation, and may lead to flash over and arcing that causes damage in the electrical part and potential catastrophic cascade failure.
• most liquid crystalline polymers exhibit relatively poor electrical tracking properties, which can limit their use to only low and medium voltage applications.
• a polymer composition comprises from about 20 wt.% to about 90 wt.% of at least one thermotropic liquid crystalline polymer, from about 1 wt.% to about 60 wt.% of inorganic particles, and from about 0.001 wt.% to about 5 wt.% of at least one functional aromatic compound having the general structure provided below in Formula (I):
• ring B is a 6-membered aromatic ring wherein 1 to 3 ring carbon atoms are optionally replaced by nitrogen or oxygen, wherein each nitrogen is optionally oxidized, and wherein ring B may be optionally fused or linked to a 5- or 6- membered aryl, heteroaryl, cycloalkyl, or heterocycly!;
• R 4 is OH or COOH
• R 5 is acyl, acyloxy, acylamino, alkoxy, alkenyl, alkyl, amino, aryl, aryloxy, carboxyl, carboxyl ester, cycloalkyl, cycloalkyloxy, hydroxyl, halo, haloalkyl, heteroaryl, heteroaryioxy, heterocyclyl, or heterocycloxy;
• n is from 0 to 4.
• n is from 1 to 3.
• the polymer composition has a comparative tracking index of about 225 volts or more, as determined in accordance with ASTM D-3638-12.
• an electronic component comprising a polymer composition.
• the polymer composition comprises at least one thermotropic liquid crystalline polymer, inorganic particles, and at least one functional aromatic compound.
• the polymer composition has a comparative tracking index of about 225 volts or more, as determined in accordance with ASTM D-3638-12.
• Fig. 1 is an exploded perspective view of one embodiment of a fine pitch electrical connector that may be formed according to the present invention
• Fig. 2 is a front view of opposing walls of the fine pitch electrical connector of Fig. 1 ;
• Fig. 3 is a schematic illustration of one embodiment of an extruder screw that may be used to form the polymer composition of the present invention
• FIGs. 4-5 are respective front and rear perspective views of an electronic component that can employ an antenna structure formed in accordance with one embodiment of the present invention.
• FIGs. 6-7 are perspective and front views of a compact camera module (“CC ”) that may be formed in accordance with one embodiment of the present invention.
• Alkyl refers to monovalent saturated aliphatic hydrocarbyl groups having from 1 to 10 carbon atoms and, in some embodiments, from 1 to 6 carbon atoms.
• C x-y alkyl refers to alkyl groups having from x to y carbon atoms.
• This term includes, by way of example, linear and branched hydrocarbyl groups such as methyl (CH 3 ), ethyl (CH 3 CH 2 ), n-propyl (CH3CH 2 CH 2 ), isopropyl ((CH 3 ) 2 CH) S n- butyl (CH3CH2CH2CH2), isobutyl ((CH 3 )2CHCH 2 ), sec-butyl ((CH 3 )(CH 3 CH 2 )CH), f- butyl ((CH 3 ) 3 C), n-pentyl (CH 3 CH 2 CH2CH 2 CH 2 ), and neopentyl ((CH 3 ) 3 CCH 2 ).
• linear and branched hydrocarbyl groups such as methyl (CH 3 ), ethyl (CH 3 CH 2 ), n-propyl (CH3CH 2 CH 2 ), isopropyl ((CH 3 ) 2 CH) S n- butyl (CH3CH2CH2
• Alkoxy refers to the group -O-alkyl. Alkoxy includes, by way of example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, t-butoxy, sec-butoxy, and n-pentoxy.
• (C x -C y )alkenyl refers to alkenyl groups having from x to y carbon atoms and is meant to include for example, ethenyl, propenyl, 1 ,3-butadienyl, and so forth.
• Ali refers to an aromatic group of from 3 to 14 carbon atoms and no ring heteroatoms and having a single ring (e.g., phenyl) or multiple condensed
• fused rings e.g., naphthyl or anthry!
• Aryl applies when the point of attachment is at an aromatic carbon atom (e.g., 5,6,7,8 tetrahydronaphthalene-2-yl is an aryl group as its point of attachment is at the 2-position of the aromatic phenyl ring).
• Aryloxy refers to the group -O-aryl, which includes, by way of example, phenoxy and naphthyloxy.
• Carboxyl or “carboxy” refers to -COOH or salts thereof.
• Carboxyl ester or “carboxy ester” refers to the groups -C(0)0-alkyl
• Cycloalkyl refers to a saturated or partially saturated cyclic group of from 3 to 14 carbon atoms and no ring heteroatoms and having a single ring or multiple rings including fused, bridged, and spiro ring systems.
• cycloalkyl applies when the point of attachment is at a non-aromatic carbon atom (e.g., 5,6,7,8,-tetrahydronaphthalene-5-yl).
• cycloalkyl includes cycloalkenyl groups, such as adamantyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, and cyclohexeny!.
• Cycloalkyioxy refers to -O cycloalkyl.
• Halo or "halogen” refers to fluoro, chloro, bromo, and iodo.
• Haloalkyl refers to substitution of alkyl groups with 1 to 5 or in some embodiments 1 to 3 halo groups.
• Heteroaryl refers to an aromatic group of from 1 to 14 carbon atoms and 1 to 6 heteroatoms selected from oxygen, nitrogen, and sulfur and includes single ring (e.g., imidazolyl) and multiple ring systems (e.g., benzimidazol-2-y! and benzimidazoi-6-yl).
• heteroaryl For multiple ring systems, including fused, bridged, and spiro ring systems having aromatic and non-aromatic rings, the term "heteroaryl” applies if there is at least one ring heteroatom and the point of attachment is at an atom of an aromatic ring ⁇ e.g., 1 ,2,3,4-tetrahydroquinolin-6-yl and 5,6,7,8- tetrahydroquinolin-3-yl).
• the nitrogen and/or the sulfur ring atom(s) of the heteroaryl group are optionally oxidized to provide for the N oxide (N ⁇ 0), sulfinyl, or sulfonyl moieties.
• heteroaryl groups include, but are not limited to, pyridyl, furanyl, thienyl, thiazoiyi, isothiazolyl, triazolyl, imidazolyl, imidazolinyl, isoxazolyi, pyrroiyl, pyrazolyl, pyridazinyl, pyrimidinyl, purinyl, phthalazyl, naphthylpryidyl, benzofuranyl, tetrahydrobenzofuranyl, isobenzofuranyl, benzothiazolyl, benzoisothiazolyl, benzotriazolyl, indolyl, isoindolyl, indolizinyl, dihydroindolyl, indazolyl, indolinyl, benzoxazolyl, quinolyl, isoquinolyl, quinolizyl, quianazolyl, quinoxalyl, tetra
• benzimidazolyl benzisoxazolyl, benzothienyl, benzopyridazinyl, pteridinyl, carbazolyl, carbolinyl, phenanthridinyl, acridinyl, phenanthrolinyl, phenazinyl, phenoxazinyl, phenothiazinyl, and phthalimidyl.
• Heteroaryloxy refers to -O-heteroaryl.
• Heterocyclic or “heterocycle” or “heterocycloalkyl” or “heterocyclyl” refers to a saturated or partially saturated cyclic group having from 1 to 14 carbon atoms and from 1 to 6 heteroatoms selected from nitrogen, sulfur, or oxygen and includes single ring and multiple ring systems including fused, bridged, and spiro ring systems.
• heterocyclic For multiple ring systems having aromatic and/or non-aromatic rings, the terms “heterocyclic”, “heterocycle”, “heterocycloalkyl”, or “heterocyclyl” apply when there is at least one ring heteroatom and the point of attachment is at an atom of a non-aromatic ring (e.g., decahydroquinolin-6-yl).
• a non-aromatic ring e.g., decahydroquinolin-6-yl
• the nitrogen and/or sulfur atom(s) of the heterocyclic group are optionally oxidized to provide for the N oxide, sulfinyl, sulfonyl moieties.
• heterocyclyl groups include, but are not limited to, azetidinyl, tetrahydropyranyl, piperidinyl, N-methyipiperidin-3-yl, piperazinyl, N-methylpyrrolidin-3-yi, 3- pyrrolidinyl, 2-pyrrolidon-1 -yl, morphoiinyl, thiomorpholinyl, imidazolidinyl, and pyrrolidinyl.
• Heterocyclyloxy refers to the group -O-heterocycyl.
• Acyl refers to the groups H-C(O)-, alkyl-C(O)-, alkenyl-C(O)-, cycloalkyl-C(O)-, aryl-C(O)-, heteroaryl-C(O)-, and heterocyclic-C(O)-.
• Acyl includes the "acetyl” group CH 3 C(0)-.
• Acyloxy refers to the groups alkyl-C(0)0-, alkenyl-C(0)0-, aryl- C(0)0-, cycloalkyl-C(0)0-, heteroaryl-C(0)0-, and heterocyclic-C(0)0-. Acyloxy includes the “acetyloxy” group CH 3 C(0)0-.
• Acylamino refers to the groups -NHC(0)alkyl, -NHC(0)alkenyl, - NHC(0)cycloalkyl, -NHC(0)aryl, -NHC ⁇ 0)heteroaryl, and -NHC(0)heterocyclic. Acylamino includes the "acetylamino" group -NHC(0)CH 3 .
• an aryl, heteroaryl, cycloalkyl, or heterocyclyl group may be substituted with from 1 to 8, in some embodiments from 1 to 5, in some embodiments from 1 to 3, and in some embodiments, from 1 to 2 substituents selected from aikyl, alkeny!, alkynyl, alkoxy, acyl, acylamino, acyioxy, amino, quaternary amino, amide, imino, amidino, aminocarbonylamino, amidinocarbonylamino, aminothiocarbonyl,
• phosphoramidate monoester cyclic phosphoramidate, cyclic phosphorodiamidate, phosphoramidate diester, sulfate, sulfonate, sulfonyl, substituted sulfonyl, sulfonyloxy, thioacyl, thiocyanate, thiol, alkyithio, etc., as well as combinations of such substituents.
• the present invention is directed to a liquid crystalline polymer composition having a relatively high comparative tracking index ("CTI"). More particularly, the composition has a CTI that is about 225 volts or more, in some embodiments about 250 volts or more, in some embodiments about 275 volts or more, in some embodiments about 300 volts or more, and in some embodiments, from about 325 volts to about 600 volts.
• CTI comparative tracking index
• the present inventors have discovered that such high CTI values can be achieved through the use of inorganic particles in combination with a functional aromatic compound. While not fully understood, it is believed that the functional
• these smaller chains can potentially form insulated regions at the surface of the polymer that hinder the formation of conductive carbonaceous deposits during the tracking process, which could otherwise lead to failure during testing.
• the polymer composition of the present invention has been found to possess excellent properties.
• the melt viscosity of the polymer composition may be low enough so that it can readily flow into the cavity of a mold having small dimensions.
• the polymer composition may have a melt viscosity of from about 0.1 to about 80 Pa-s, in some embodiments from about 0.5 to about 50 Pa-s, and in some embodiments, from about 1 to about 30 Pa-s, determined at a shear rate of 1000 seconds "1 .
• Melt viscosity may be determined in accordance with ISO Test No. 1 443 at a temperature that is 15°C higher than the melting temperature of the composition (e.g., 350°C).
• the composition may still possess a relatively high impact strength, which is useful when forming small parts for high voltage electronic devices.
• the composition may, for instance, possess a Charpy notched impact strength greater than about 4 kJ/m 2 , in some embodiments from about 5 to about 40 kJ/m 2 , and in some embodiments, from about 6 to about 30 kJ/m 2 , measured at 23°C according to ISO Test No. 179-1 ) (technically equivalent to ASTM D256, Method B).
• the tensile and fiexural mechanical properties of the composition may also be good.
• the polymer composition may exhibit a tensile strength of from about 20 to about 500 MPa, in some embodiments from about 50 to about 400 MPa, and in some embodiments, from about 100 to about
• a tensile break strain of about 0.5% or more, in some embodiments from about 0.6% to about 20%, and in some embodiments, from about 0.8% to about
• tensile modulus of from about 5,000 MPa to about 30,000 MPa, in some embodiments from about 8,000 MPa to about 20,000 MPa, and in some embodiments, from about 10,000 MPa to about 15,000 MPa.
• the tensile properties may be determined in accordance with ISO Test No. 527 (technically equivalent to ASTM D638) at 23°C.
• the polymer composition may also exhibit a flexural strength of from about 20 to about 500 MPa, in some embodiments from about 50 to about 400 MPa, and in some embodiments, from about 100 to about 350 MPa; a flexural break strain of about 0.5% or more, in some embodiments from about 0.6% to about 20%, and in some embodiments, from about 0.8% to about 3.5%; and/or a flexural modulus of from about 5,000 MPa to about 30,000 MPa, in some embodiments from about 8,000 MPa to about 20,000 MPa, and in some embodiments, from about 0,000 MPa to about 15,000 MPa.
• the flexural properties may be determined in accordance with ISO Test No. 178 (technically equivalent to ASTM D790) at 23°C.
• the polymer composition may also possess improved flame resistance performance, even in the absence of conventional flame retardants.
• the flame resistance of the composition may, for instance, be determined in accordance the procedure of Underwriter's Laboratory Bulletin 94 entitled “Tests for Flammability of Plastic Materials, UL94.” Several ratings can be applied based on the time to extinguish (total flame time) and ability to resist dripping as described in more detail below. According to this procedure, for example, a molded part formed from the composition of the present invention may achieve a
• V0 rating which means that the part has a total flame time of 50 seconds or less and a total number of drips of burning particles that ignite cotton of 0, determined at a given part thickness (e.g., 0.25 or 0.8 mm).
• a molded part formed from the composition of the present invention may exhibit a total flame time of about 50 seconds or less, in some embodiments about 45 seconds or less, and in some embodiments, from about 1 to about 40 seconds.
• the total number of drips of burning particles produced during the UL94 test may be 3 or less, in some embodiments 2 or less, and in some embodiments, 1 or less (e.g., 0).
• Such testing may be performed after conditioning for 48 hours at 23°C and 50% relative humidity.
• the relative concentration of functional aromatic compounds and inorganic particles in the composition may be selected in the present invention to achieve the desired properties. Surprisingly, the present inventors have discovered that relatively low concentrations can significantly improve the CTI and meit viscosity.
• functional aromatic compounds typically constitute from about 0.001 wt.% to about 5 wt.%, in some embodiments from about 0.01 wt.% to about 1 wt.%, and in some embodiments, from about 0.05 wt.% to about 0.5 wt.% of the polymer composition.
• the amount of inorganic particles may likewise range from about 1 wt.% to about 60 wt.%, in some embodiments from about 5 wt.% to about 55 wt.%, in some embodiments, from about 15 wt.% to about 50 wt.%. While the concentration of the liquid crystalline polymers may generally vary based on the presence of other optional features
• components they are typically present in an amount of from about 20 wt.% to about 90 wt.%, in some embodiments from about 30 wt.% to about 80 wt.%, and in some embodiments, from about 40 wt.% to about 70 wt.%.
• thermotropic liquid crystalline polymer generally has a high degree of crystallinity that enables it to effectively fill the small spaces of a mold.
• Suitable thermotropic liquid crystalline polymers may include aromatic polyesters, aromatic poly(esteramides), aromatic poly(estercarbonates), aromatic
• polyamides, etc. may likewise contain repeating units formed from one or more aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic amines, aromatic diamines, etc., as well as combinations thereof.
• Aromatic polyesters for instance, may be obtained by polymerizing
• aromatic hydroxycarboxylic acids (1 ) two or more aromatic hydroxycarboxylic acids; (2) at least one aromatic hydroxycarboxylic acid, at least one aromatic dicarboxylic acid, and at least one aromatic diol; and/or (3) at least one aromatic dicarboxylic acid and at least one aromatic diol.
• suitable aromatic hydroxycarboxylic acids include, 4- hydroxybenzoic acid; 4-hydroxy-4'-biphenylcarboxylic acid; 2-hydroxy-6-naphthoic acid; 2-hydroxy-5-naphthoic acid; 3-hydroxy-2-naphthoic acid; 2-hydroxy-3- naphthoic acid; 4'-hydroxyphenyl-4-benzoic acid; 3'-hydroxyphenyl-4-benzoic acid;
• aromatic dicarboxylic acids include terephthalic acid; isophthalic acid; 2,6-naphthalenedicarboxylic acid; diphenyl ether-4,4'-dicarboxylic acid; 1 ,6-naphthalenedicarboxylic acid; 2,7- naphthalenedicarboxylic acid; 4,4'-dicarboxybiphenyi; bis(4-carboxyphenyl)ether; bis(4-carboxyphenyl)butane; bis(4-carboxyphenyl)ethane; bis ⁇ 3- carboxyphenyl)ether; bis(3-carboxyphenyl)ethane, etc., as well as alkyl, alkoxy, aryl and halogen substituents thereof.
• aromatic diols examples include hydroquinone; resorcinol; 2,6-dihydroxynaphthalene; 2,7-dihydroxynaphthalene; 1 ,6-dihydroxynaphthalene; 4,4'-dihydroxybiphenyl; 3,3'-dihydroxybiphenyl; 3,4'- dihydroxybiphenyl; 4,4-dihydroxybiphenyl ether; bis(4-hydroxyphenyl)ethane, etc., as well as alkyl, aikoxy, aryl and halogen substituents thereof.
• the synthesis and structure of these and other aromatic polyesters may be described in more detail in U.S. Patent Nos. 4,161 ,470; 4,473,682; 4,522,974; 4,375,530; 4,318,841 ;
• Liquid crystalline polyesteramides may likewise be obtained by polymerizing (1 ) at least one aromatic hydroxycarboxylic acid and at least one aromatic aminocarboxylic acid; (2) at least one aromatic hydroxycarboxylic acid, at least one aromatic dicarboxylic acid, and at least one aromatic amine and/or diamine optionally having phenolic hydroxy groups; and (3) at least one aromatic dicarboxylic acid and at least one aromatic amine and/or diamine optionally having phenolic hydroxy groups.
• Suitable aromatic amines and diamines may include, for instance, 3-aminophenol; 4-aminophenol; 1 ,4-phenylenediamine; 1 ,3- phenylenediamine, etc., as well as alkyl, alkoxy, aryl and halogen substituents thereof.
• the aromatic po!yesteramide contains monomer units derived from 2,6-hydroxynaphthoic acid, terephthalic acid, and 4- aminophenol.
• the aromatic polyesteramide contains monomer units derived from 2,6-hydroxynaphthoic acid, and 4-hydroxybenzoic acid, and 4-aminophenol, as well as other optional monomers (e.g., 4,4 - dihydroxybiphenyl and/or terephthalic acid).
• the synthesis and structure of these and other aromatic poly(esteramides) may be described in more detail in U.S. Patent Nos. 4,339,375; 4,355,132; 4,351 ,917; 4,330,457; 4,351 ,918; and
• the liquid crystalline polymer may be a "low naphthenic" polymer to the extent that it contains a minimal content of repeating units derived from naphthenic hydroxycarboxylic acids and naphthenic dicarboxylic acids, such as naphthalene-2,6-dicarboxylic acid (“NDA”), 6-hydroxy-
• HNA 2-naphthoic acid
• the total amount of repeating units derived from naphthenic hydroxycarboxylic and/or dicarboxylic acids is typically no more than 15 mol.%, in some embodiments no more than about 13 mol.%, in some embodiments no more than about 10 mol.%, in some embodiments no more than about 8 mol.%, and in some embodiments, from 0 mol.% to about 5 mol.% of the polymer (e.g., 0 mol.%).
• a "low naphthenic" aromatic polyester may be formed that contains monomer repeat units derived from 4- hydroxybenzoic acid (“HBA”), terephthalic acid (“TA”) and/or isophthalic acid
• the monomer units derived from 4-hydroxybenzoic acid (“HBA”) may constitute from about 40 mol.% to about
• TA terephthalic acid
• IA isophthalic acid
• Other possible monomer repeat units include aromatic diols, such as 4,4'-biphenol (“BP”), hydroquinone
• BP HQ
• APAP aromatic amides, such as acetaminophen
• BP, HQ, and/or APAP may each constitute from about 1 mol.% to about 30 mol.%, in some embodiments from about 2 mol.% to about 25 mol.%, and in some embodiments, from about 3 mol.% to about 20 mol.% when employed.
• the polymer may also contain a small amount of 6-hydroxy-2-naphthoic acid (“HNA”) within the ranges noted above.
• HNA 6-hydroxy-2-naphthoic acid
• the liquid crystalline polymers may be prepared by introducing the appropriate monomer(s) (e.g., aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic amine, aromatic diamine, etc.) into a reactor vessel to initiate a polycondensation reaction.
• the particular conditions and steps employed in such reactions are well known, and may be described in more detail in U.S. Patent No. 4,161 ,470 to Calundann; U.S. Patent No. 5,616,680 to Linstid. HI. et al.: U.S. Patent No. 6,114,492 to Linstid, 111, et ah; U.S. Patent No. 6,514,611 to Shepherd, et al.: and WO 2004/058851 to Waggoner.
• the vessel employed for the reaction is not especially limited, although it is typically desired to employ one that is commonly used in reactions of high viscosity fluids.
• reaction vessel may include a stirring tank-type apparatus that has an agitator with a variably-shaped stirring blade, such as an anchor type, multistage type, spiral-ribbon type, screw shaft type, etc., or a modified shape thereof.
• a mixing apparatus commonly used in resin kneading such as a kneader, a roll mill, a Banbury mixer, etc.
• the reaction may proceed through the acetylation of the monomers as referenced above and known the art. This may be accomplished by adding an acetylating agent (e.g., acetic anhydride) to the monomers.
• acetylation is generally initiated at temperatures of about 90°C.
• reflux may be employed to maintain vapor phase temperature below the point at which acetic acid byproduct and anhydride begin to distill.
• Temperatures during acetylation typically range from between 90°C to 150°C, and in some embodiments, from about 1 10°C to about 150°C. If reflux is used, the vapor phase temperature typically exceeds the boiling point of acetic acid, but remains low enough to retain residual acetic anhydride. For example, acetic anhydride vaporizes at temperatures of about 140°C. Thus, providing the reactor with a vapor phase reflux at a temperature of from about 1 10°C to about 130°C is particularly desirable. To ensure substantially complete reaction, an excess amount of acetic anhydride may be employed. The amount of excess anhydride will vary depending upon the particular acetylation conditions employed, including the presence or absence of reflux.
• Acetylation may occur in a separate reactor vessel, or it may occur in situ within the polymerization reactor vessel. When separate reactor vessels are employed, one or more of the monomers may be introduced to the acetylation reactor and subsequently transferred to the polymerization reactor. Likewise, one or more of the monomers may also be directly introduced to the reactor vessel without undergoing pre-acetylation.
• a catalyst may be optionally employed, such as metal salt catalysts (e.g., magnesium acetate, tin(l) acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, etc.) and organic compound catalysts (e.g., N-methylimidazole).
• metal salt catalysts e.g., magnesium acetate, tin(l) acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, etc.
• organic compound catalysts e.g., N-methylimidazole
• the reaction mixture is generally heated to an elevated temperature within the polymerization reactor vessel to initiate melt polycondensation of the reactants.
• Polycondensation may occur, for instance, within a temperature range of from about 2 0°C to about 400°C, and in some embodiments, from about
• one suitable technique for forming an aromatic polyester may include charging precursor monomers (e.g., 4- hydroxybenzoic acid and 2,6-hydroxynaphthoic acid) and acetic anhydride into the reactor, heating the mixture to a temperature of from about 90°C to about 150°C to acetylize a hydroxyl group of the monomers (e.g., forming acetoxy), and then increasing the temperature to a temperature of from about 210°C to about 400°C to carry out melt polycondensation. As the final polymerization temperatures are approached, volatile byproducts of the reaction (e.g., acetic acid) may also be removed so that the desired molecular weight may be readily achieved.
• the reaction mixture is generally subjected to agitation during polymerization to ensure good heat and mass transfer, and in turn, good material homogeneity.
• the rotational velocity of the agitator may vary during the course of the reaction, but typically ranges from about 10 to about 100 revolutions per minute ("rpm"), and in some embodiments, from about 20 to about 80 rpm.
• the polymerization reaction may also be conducted under vacuum, the application of which facilitates the removal of volatiles formed during the final stages of polycondensation.
• the vacuum may be created by the application of a suctional pressure, such as within the range of from about 5 to about 30 pounds per square inch (“psi”), and in some embodiments, from about 10 to about 20 psi.
• the molten polymer may be discharged from the reactor, typically through an extrusion orifice fitted with a die of desired configuration, cooled, and collected. Commonly, the melt is
• the resin may also be in the form of a strand, granule, or powder. While unnecessary, it should also be understood that a subsequent solid phase polymerization may be conducted to further increase molecular weight.
• solid-phase polymerization When carrying out solid-phase polymerization on a polymer obtained by melt polymerization, it is typically desired to select a method in which the polymer obtained by melt polymerization is solidified and then pulverized to form a powdery or flake-like polymer, followed by performing solid polymerization method, such as a heat treatment in a temperature range of 200°C to 350°C under an inert atmosphere (e.g., nitrogen).
• the resulting liquid crystalline polymer typically may have a high number average molecular weight ( n) of about 2,000 grams per mole or more, in some embodiments from about 4,000 grams per mole or more, and in some embodiments, from about 5,000 to about 30,000 grams per mole.
• n number average molecular weight
• polymers having a lower molecular weight such as less than about 2,000 grams per mole, using the method of the present invention.
• the intrinsic viscosity of the polymer which is generally proportional to molecular weight, may also be relatively high.
• the intrinsic viscosity may be about about 4 deciliters per gram ("dL/g") or more, in some embodiments about 5 dL/g or more, in some
• Intrinsic viscosity may be determined in accordance with ISO-1628-5 using a 50/50 (v/v) mixture of pentafluorophenoi and
• any of a variety of inorganic particles may generally be employed in the composition of the present invention, such as diatomaceous earth and wollastonite; metal oxides (e.g., iron oxides, titanium oxides, barium oxides, zinc oxides and alumina); metal carbonates (e.g., calcium carbonate and magnesium carbonate); metal sulfates (e.g., calcium sulfate and barium sulfate); phosphates of aluminum, calcium, magnesium, zinc, cerium and mixed metals; titanates of magnesium, calcium, aluminum and mixed metals; fluorides of magnesium and calcium; silicates of zinc, zirconium, calcium, barium, magnesium, mixed alkaline earths and naturally occurring silicate minerals; aluminosilicates of alkali and alkaline earths, and naturally occurring aluminosilicates; oxalates of calcium, zinc, magnesium, aluminum and mixed metals; aluminates of zinc, calcium, magnesium, and mixed alkaline earth silicon carbide
• Particularly suitable particles include those formed from titanium dioxide.
• the surface of such particles may be untreated, or may be coated with an oxide of a metal (e.g., aluminum, silicon or zirconium) or organic acid (e.g., stearic acid or tauric acid).
• Suitable crystal forms of titanium dioxide may include anatase and rutile.
• the titanium dioxide particles may possess any discrete form such as particles, flakes, etc.
• the size of the inorganic particles may generally vary, but is typically about 5 micrometers or less, in some embodiments about 2 micrometers or less, and in some embodiments, from about 10 to about 500 nanometers. Aggregates or agglomerates of inorganic particles may also be employed in which the primary particle size and/or agglomerate size is within the ranges noted above.
• the polymer composition of the present invention also contains functional aromatic compound.
• Such compounds generally contain one or more carboxyl and/or hydroxyl functional groups that can react with the polymer chain to shorten its length as described above.
• the compound may also be able to combine smaller chains of the polymer together after they have been cut to help maintain the mechanical properties of the composition even after its melt viscosity has been reduced.
• the functional compound typically has the general structure provided below in Formula (I):
• ring B is a 6-membered aromatic ring wherein 1 to 3 ring carbon atoms are optionally replaced by nitrogen or oxygen, wherein each nitrogen is optionally oxidized, and wherein ring B may be optionally fused or linked to a 5- or 6- membered aryl, heteroaryl, cycloalkyl, or heterocyclyl;
• R 4 is OH or COOH
• R 5 is acyl, acyloxy (e.g., acetyloxy), acylamino (e.g., acetylamino), alkoxy, alkenyi, alkyl, amino, aryl, aryioxy, carboxyl, carboxyl ester, cycloalkyl,
• cycloalkyloxy hydroxyl, halo, haloalkyl, heteroaryl, heteroaryloxy, heterocyclyl, or heterocycloxy;
• m is from 0 to 4, in some embodiments from 0 to 2, and in some
• n is from 1 to 3, and in some embodiments, from 1 to 2.
• suitable metal counterions may include transition metal counterions (e.g., copper, iron, etc.), alkali metal counterions (e.g., potassium, sodium, etc.), alkaline earth metal counterions (e.g., calcium, magnesium, etc.), and/or main group metal counterions (e.g., aluminum).
• B is phenyl in Formula (I) such that the resulting phenolic compounds have the following general formula (II):
• R 4 is OH or COOH
• Re is acyl, acyloxy, acylamino, alkoxy, alkenyl, a!kyl, amino, carboxyl, carboxyl ester, hydroxyl, halo, or haloalkyl;
• q is from 0 to 4, in some embodiments from 0 to 2, and in some
• phenolic compounds include, for instance, benzoic acid (q is 0); 4-hydroxybenzoic acid (R 4 is COOH, Re is OH, and q is 1 ); phthalic acid (R 4 is COOH, R 6 is COOH, and q is 1 ); isophthalic acid (R 4 is COOH, R 6 is COOH, and q is 1 ); terephthalic acid (R 4 is COOH, R 6 is COOH, and q is 1 ); 2-methylterephthalic acid (R 4 is COOH, R 6 is COOH, and CH 3 and q is 2); phenol (R4 is OH and q is 0); sodium phenoxide (R 4 is OH and q is 0); hydroquinone (R is OH, R 6 is OH, and q is 1 ); resorcinol (R 4 is OH, R 6 is OH, and q is 1 ); 4-hydroxybenzoic acid (R4 is OH,
• B is phenyl and R5 is phenyl in Formula (I) above such that the di henolic compounds have the following general formula (III):
• R4 IS COOH or OH
• Re is acyl, acyloxy, acylamino, alkoxy, alkenyl, alkyl, amino, aryl, aryloxy, carboxyl, carboxyl ester, cycloaikyl, cycloalkyloxy, hydroxyl, halo, haloalkyl, heteroaryl, heteroaryloxy, heterocyclyl, or heterocycloxy; and
• q is from 0 to 4, in some embodiments from 0 to 2, and in some
• diphenolic compounds include, for instance, 4-hydroxy-4'-biphenylcarboxylic acid (R 4 is COOH, R 6 is OH, and q is 1 ); 4'-hydroxyphenyl-4-benzoic acid (R 4 is COOH, Re is OH, and q is 1 ); 3'-hydroxyphenyl-4-benzoic acid (R4 is COOH, R 6 is OH, and q is 1 ); 4'- hydroxyphenyl-3-benzoic acid (R 4 is COOH, Re is OH, and q is 1 ); 4,4'-bibenzoic acid (R 4 is COOH, R 6 is COOH, and q is 1 ); (R 4 is OH, R 6 is OH, and q is 1 ); 3,3'- biphenol (R 4 is OH, R 6 is OH, and q is 1 ); 3,4'-biphenol (R 4 is OH, R 6 is OH, and q is 1);
• B is naphthenyl in Formula (I) above such that the resulting naphthenic compounds have the following general formula (IV):
• R 4 is OH or COOH
• R 6 is acyl, acyloxy, acylamino, alkoxy, alkenyl, alkyl, amino, aryl, aryloxy, carboxyl, carboxyl ester, cycloalkyl, cycioalky!oxy, hydroxyl, halo, haloalkyl, heteroaryl, heteroaryioxy, heterocyclyl, or heterocycloxy; and
• q is from 0 to 4, in some embodiments from 0 to 2, and in some
• naphthenic compounds from 0 to 1 .
• naphthenic compounds include, for instance, 1 -naphthoic acid (R 4 is COOH and q is 0); 2-naphthoic acid
• R 4 is COOH and q is 0; 2-hydroxy-6-naphthoic acid (R 4 is COOH, R 6 is OH, and q is 1 ); 2-hydroxy-5-naphthoic acid (R 4 is COOH, R 6 is OH, and q is 1 ); 3-hydroxy-
• R 4 is COOH, R 6 is OH, and q is 1 ); 2,6-naphthalenedicarboxylic acid (R 4 is
• R 6 is COOH, and q is 1 ); 2,3-naphthalenedicarboxylic acid (R 4 is COOH,
• Re is COOH, and q is 1); 2-hydroxy-naphthelene (R 4 is OH and q is 0); 2-hydroxy-
• 6-naphthoic acid (R 4 is OH, R 6 is COOH, and q is 1 ); 2-hydroxy-5 ⁇ naphthoic acid
• the polymer composition may contain an aromatic diol, such as hydroquinone, resorcinol, 4,4 -biphenol, etc., as well as combinations thereof.
• aromatic diols may constitute from about 0.01 wt.% to about 1 wt.%, and in some embodiments, from about 0.05 wt.% to about 0.4 wt.% of the polymer composition.
• An aromatic carboxylic acid may also be employed in certain embodiments, either alone or in conjunction with the aromatic diol.
• Aromatic carboxylic acids may constitute from about 0.001 wt.% to about 0.5 wt.%, and in some embodiments, from about 0.005 wt.% to about 0.1 wt.% of the polymer composition.
• a combination of an aromatic diol (R4 and Re are OH in the formulae above) (e.g., 4,4'-biphenol) and an aromatic dicarboxylic acid (R 4 and R 6 are COOH in the formulae above) (e.g., 2,6- naphthelene dicarboxylic acid) is employed in the present invention to help achieve the desired CTl values.
• non-aromatic functional compounds may also be employed in the present invention. Such compounds may serve a variety of purposes, such as assisting in the improvement of the CTl values, reducing melt viscosity, etc.
• One such non-aromatic functional compound is water.
• water can be added in a form that under process conditions generates water.
• the water can be added as a hydrate that under the process conditions (e.g., high temperature) effectively "loses" water.
• hydrates include alumina trihydrate, copper sulfate pentahydrate, barium chloride dihydrate, calcium sulfate dehydrate, etc., as well as
• the hydrates may constitute from about
• wt.% 0.02 wt.% to about 2 wt.%, and in some embodiments, from about 0.05 wt.% to about 1 wt.% of the polymer composition.
• a mixture of an aromatic diol, hydrate, and aromatic dicarboxylic acid are employed in the composition.
• the weight ratio of hydrates to aromatic diols is typically from about 0.5 to about 8, in some embodiments from about 0.8 to about 5, and in some embodiments, from about 1 to about 5.
• Various fillers may also be incorporated in the polymer composition if desired.
• fibers may be employed in the polymer composition to improve the mechanical properties.
• Such fibers generally have a high degree of tensile strength relative to their mass.
• the ultimate tensile strength of the fibers is typically from about 1 ,000 to about 15,000 Megapascals ("MPa"), in some embodiments from about 2,000 MPa to about 10,000 Pa, and in some embodiments, from about 3,000 MPa to about 6,000 MPa.
• the high strength fibers may be formed from materials that are also generally insulative in nature, such as glass, ceramics (e.g., alumina or silica), aramids (e.g., Kevlar® marketed by E. I.
• Glass fibers are particularly suitable, such as E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1 -glass, S2-glass, etc., and mixtures thereof.
• the volume average length of the fibers may be from about 50 to about 400 micrometers, in some embodiments from about 80 to about 250 micrometers, in some embodiments from about 100 to about 200 micrometers, and in some embodiments, from about 110 to about 180 micrometers.
• the fibers may also have a narrow length distribution. That is, at least about 70% by volume of the fibers, in some embodiments at least about 80% by volume of the fibers, and in some embodiments, at least about 90% by volume of the fibers have a length within the range of from about 50 to about 400 micrometers, in some embodiments from about 80 to about 250 micrometers, in some
• the fibers may also have a relatively high aspect ratio (average length divided by nominal diameter) to help improve the mechanical properties of the resulting polymer composition.
• the fibers may have an aspect ratio of from about 2 to about 50, in some embodiments from about 4 to about 40, and in some embodiments, from about 5 to about 20 are particularly beneficial.
• the fibers may, for example, have a nominal diameter of about 10 to about 35 micrometers, and in some embodiments, from about 15 to about 30 micrometers.
• the relative amount of the fibers in the polymer composition may also be selectively controlled to help achieve the desired mechanical properties without adversely impacting other properties of the composition, such as its flowability.
• the fibers typically constitute from about 2 wt.% to about 40 wt.%, in some embodiments from about 5 wt.% to about 35 wt.%, and in some embodiments, from about 6 wt.% to about 30 wt.% of the polymer composition.
• the fibers may be employed within the ranges noted above, one particularly beneficial and surprising aspect of the present invention is that small fiber contents may be employed while still achieving the desired mechanical properties.
• the narrow length distribution of the fibers can help achieve excellent mechanical properties, thus allowing for the use of a smaller amount of fibers.
• the fibers can be employed in small amounts such as from about 2 wt.% to about 20 wt.%, in some embodiments, from about 5 wt.% to about 6 wt.%, and in some
• Mineral fillers may also be employed in the polymer composition to help achieve the desired properties and/or color.
• such mineral fillers typically constitute from about 5% by weight to about 40% by weight, in some embodiments from about 10% by weight to about 35% by weight, and in some embodiments, from about 10% by weight to about 30% by weight of the polymer composition.
• Clay minerals may be particularly suitable for use in the present invention. Examples of such clay minerals include, for instance, talc
• silicate fillers may also be employed, such as calcium silicate, aluminum silicate, mica, diatomaceous earth, wollastonite, and so forth.
• Mica for instance, may be a particularly suitable mineral for use in the present invention. There are several chemically distinct mica species with considerable variance in geologic
• the term "mica” is meant to generically include any of these species, such as muscovite (KAI 2 (AiSi 3 )OiQ(OH)2), biotite (K(Mg,Fe) 3 (AISi 3 )Oio(OH) 2 ), phlogopite
• Still other additives that can be included in the composition may include, for instance, antimicrobials, pigments, antioxidants, stabilizers, surfactants, waxes, solid solvents, flame retardants, anti-drip additives, and other materials added to enhance properties and processability.
• Lubricants may also be employed in the polymer composition that are capable of withstanding the processing conditions of the liquid crystalline polymer without substantial decomposition.
• examples of such lubricants include fatty acids esters, the salts thereof, esters, fatty acid amides, organic phosphate esters, and hydrocarbon waxes of the type commonly used as lubricants in the processing of engineering plastic materials, including mixtures thereof.
• Suitable fatty acids typically have a backbone carbon chain of from about 12 to about 60 carbon atoms, such as myristic acid, palmitic acid, stearic acid, arachic acid, montanic acid, octadecinic acid, parinric acid, and so forth.
• Suitable esters include fatty acid esters, fatty alcohol esters, wax esters, glycerol esters, glycol esters and complex esters.
• Fatty acid amides include fatty primary amides, fatty secondary amides, methylene and ethylene bisamides and alkanolamides such as, for example, palmitic acid amide, stearic acid amide, oleic acid amide, ⁇ , ⁇ '- ethylenebisstearamide and so forth.
• metal salts of fatty acids such as calcium stearate, zinc stearate, magnesium stearate, and so forth; hydrocarbon waxes, including paraffin waxes, polyolefin and oxidized polyolefin waxes, and micro-crystalline waxes.
• Particularly suitable lubricants are acids, salts, or amides of stearic acid, such as pentaerythritol tetrastearate, calcium stearate, or ⁇ , ⁇ '-ethylenebisstearamide.
• the lubricant(s) typically constitute from about 0.05 wt.% to about 1.5 wt.%, and in some embodiments, from about 0.1 wt.% to about 0.5 wt.% (by weight) of the polymer composition.
• the liquid crystalline polymer, inorganic particles, functional aromatic compound, and other optional additives may be melt blended together within a temperature range of from about 200°C to about 450°C, in some embodiments, from about 220°C to about 400°C, and in some embodiments, from about 250°C to about 350°C to form the polymer composition. Any of a variety of melt blending techniques may generally be employed in the present invention.
• the components may be supplied separately or in combination to an extruder that includes at least one screw rotatably mounted and received within a barrel (e.g., cylindrical barrel) and may define a feed section and a melting section located downstream from the feed section along the length of the screw.
• a barrel e.g., cylindrical barrel
• the extruder may be a single screw or twin screw extruder.
• a single screw extruder 80 contains a housing or barrel 114 and a screw 120 rotatably driven on one end by a suitable drive 124 (typically including a motor and gearbox).
• a twin-screw extruder may be employed that contains two separate screws.
• the configuration of the screw is not particularly critical to the present invention and it may contain any number and/or orientation of threads and channels as is known in the art.
• the screw 120 contains a thread that forms a generally helical channel radially extending around a core of the screw 120.
• a hopper 40 is located adjacent to the drive 124 for supplying the liquid crystalline polymer and/or other materials (e.g., inorganic particles and/or functional compound) through an opening in the barrel 114 to the feed section 132.
• the drive 124 Opposite the drive 124 is the output end 144 of the extruder 80, where extruded plastic is output for further processing.
• a feed section 132 and melt section 134 are defined along the length of the screw 120.
• the feed section 132 is the input portion of the barrel 114 where the liquid crystalline polymer, inorganic particles, and/or the functional compound are added.
• the melt section 134 is the phase change section in which the liquid crystalline polymer is changed from a solid to a liquid. While there is no precisely defined delineation of these sections when the extruder is manufactured, it is well within the ordinary skill of those in this art to reliably identify the feed section 132 and the melt section 134 in which phase change from solid to liquid is occurring.
• the extruder 80 may also have a mixing section 136 that is located adjacent to the output end of the barrel 114 and downstream from the melting section 134.
• one or more distributive and/or dispersive mixing elements may be employed within the mixing and/or melting sections of the extruder.
• Suitable distributive mixers for single screw extruders may include, for instance, Saxon, Dulmage, Cavity Transfer mixers, etc.
• suitable dispersive mixers may include Blister ring, Leroy/ addock, CRD mixers, etc.
• the mixing may be further improved by using pins in the barrel that create a folding and reorientation of the polymer melt, such as those used in Buss Kneader extruders, Cavity Transfer mixers, and Vortex Intermeshing Pin mixers.
• fibers can also be added to the hopper 40 or at a location downstream therefrom.
• fibers may be added a location downstream from the point at which the liquid crystalline polymer is supplied, but yet prior to the melting section.
• a hopper 42 is shown that is located within a zone of the feed section 132 of the extruder 80.
• the fibers supplied to the hopper 42 may be initially relatively long, such as having a volume average length of from about 1 ,000 to about 5,000 micrometers, in some embodiments from about 2,000 to about 4,500
• the polymer can act as an abrasive agent for reducing the size of the fibers to a volume average length and length distribution as indicated above.
• the ratio of the length ("L") to diameter (“D") of the screw may be selected to achieve an optimum balance between throughput and fiber length reduction.
• the L/D value may, for instance, range from about 15 to about
• the length of the screw may, for instance, range from about 0.1 to about 5 meters, in some embodiments from about 0.4 to about 4 meters, and in some embodiments, from about 0.5 to about 2 meters.
• the diameter of the screw may likewise be from about 5 to about 150 millimeters, in some embodiments from about 10 to about 120 millimeters, and in some embodiments, from about 20 to about 80 millimeters.
• the L/D ratio of the screw after the point at which the fibers are supplied may also be controlled within a certain range.
• the screw has a blending length (“L B ”) that is defined from the point at which the fibers are supplied to the extruder to the end of the screw, the blending length being less than the total length of the screw.
• L B blending length
• the L B /D ratio of the screw after the point at which the fibers are supplied is typically from about 4 to about 20, in some embodiments from about 5 to about 15, and in some embodiments, from about 6 to about 0.
• the speed of the screw may be selected to achieve the desired residence time, shear rate, melt processing temperature, etc.
• an increase in frictiona! energy results from the shear exerted by the turning screw on the materials within the extruder and results in the fracturing of the fibers, if employed.
• the degree of fracturing may depend, at least in part, on the screw speed.
• the screw speed may range from about 50 to about 800 revolutions per minute ("rpm"), in some embodiments from about 70 to about 50 rpm, and in some embodiments, from about 80 to about 120 rpm.
• the apparent shear rate during melt blending may also range from about 100 seconds "1 to about 10,000 seconds “1 , in some embodiments from about 500 seconds “1 to about 5000 seconds “1 , and in some embodiments, from about 800 seconds “1 to about 1200 seconds “1 .
• the apparent shear rate is equal to 40/ R 3 , where Q is the volumetric flow rate ("m 3 /s") of the polymer melt and R is the radius ("m") of the capillary (e.g., extruder die) through which the melted polymer flows.
• the length of the fibers is reduced within the extruder. It should be understood, however, that this is by no means a requirement of the present invention.
• the fibers may simply be supplied to the extruder at the desired length.
• the fibers may, for example, be supplied at the mixing and/or melting sections of the extruder, or even at the feed section in conjunction with the liquid crystalline polymer.
• fibers may not be employed at all.
• the polymer composition may be molded into any of a variety of different shaped parts using techniques as is known in the art.
• the shaped parts may be molded using a one-component injection molding process in which dried and preheated plastic granules are injected into the mold. Regardless of the molding technique employed, it has been
• the polymer composition of the present invention which possesses the unique combination of a high CTl, high flowability and good mechanical properties, is particularly well suited for electronic parts having a small dimensional tolerance.
• Such parts generally contain at least one micro-sized dimension (e.g., thickness, width, height, etc.), such as from about 500 micrometers or less, in some embodiments from about 50 to about 450 micrometers, and in some embodiments, from about 100 to about 400
• One such part is a fine pitch electrical connector. More particularly, such electrical connectors are often employed to detachably mount a central processing unit (“CPU") to a printed circuit board.
• the connector may contain insertion passageways that are configured to receive contact pins. These passageways are defined by opposing walls, which may be formed from a thermoplastic resin.
• the pitch of these pins is generally small to accommodate a large number of contact pins required within a given space. This, in turn, requires that the pitch of the pin insertion passageways and the width of opposing walls that partition those passageways are also small.
• the walls may have a width of from about 500 micrometers or less, in some embodiments from about 50 to about 450 micrometers, and in some embodiments, from about 100 to about 400
• the polymer composition of the present invention is particularly well suited to form the walls of a fine pitch connector.
• FIG. 1 One particularly suitable fine pitch electrical connector is shown in Fig. 1.
• An electrical connector 200 is shown that a board-side portion C2 that can be mounted onto the surface of a circuit board P.
• the connector 200 may also include a wiring material-side portion C1 structured to connect discrete wires 3 to the circuit board P by being coupled to the board-side connector C2.
• the board- side portion C2 may include a first housing 10 that has a fitting recess 10a into which the wiring material-side connector C1 is fitted and a configuration that is slim and long in the widthwise direction of the housing 10.
• the wiring material-side portion C1 may likewise include a second housing 20 that is slim and long in the widthwise direction of the housing 20.
• a plurality of terminal-receiving cavities 22 may be provided in parallel in the widthwise direction so as to create a two-tier array including upper and lower terminal- receiving cavities 22.
• a terminal 5, which is mounted to the distal end of a discrete wire 3, may be received within each of the terminal-receiving cavities 22.
• locking portions 28 may also be provided on the housing 20 that correspond to a connection member (not shown) on the board- side connector C2.
• the interior walls of the first housing 10 and/or second housing 20 may have a relatively small width dimension, and can be formed from the polymer composition of the present invention.
• the walls are, for example, shown in more detail in Fig. 2.
• insertion passageways or spaces 225 are defined between opposing walls 224 that can accommodate contact pins.
• the walls 224 have a width "w" that is within the ranges noted above.
• fibers e.g., element 400
• such fibers may have a volume average length and narrow length distribution within a certain range to best match the width of the walls.
• the ratio of the width of at least one of the walls to the volume average length of the fibers is from about 0.8 to about 3.2, in some embodiments from about 1.0 to about 3.0, and in some embodiments, from about 1.2 to about 2.9.
• any other portion of the housing may also be formed from the polymer
• the connector may also include a shield that encloses the housing.
• Some or all of the shield may be formed from the polymer composition of the present invention.
• the housing and the shield can each be a one-piece structure unitarily molded from the polymer composition.
• the shield can be a two-piece structure that includes a first shell and a second shell, each of which may be formed from the polymer composition of the present invention.
• the polymer composition may also be used in a wide variety of other components.
• the polymer composition may be molded into a planar substrate for use in an electronic component.
• the substrate may be thin, such as having a thickness of about 500 micrometers or less, in some embodiments from about 50 to about 450 micrometers, and in some embodiments, from about 00 to about 400 micrometers.
• the planar substrate may be applied with one or more conductive elements using a variety of known techniques (e.g., laser direct structuring, electroplating, etc.).
• the conductive elements may serve a variety of different purposes.
• the conductive elements form an integrated circuit, such as those used in SIM cards.
• the conductive elements form antennas of a variety of different types, such as antennae with resonating elements that are formed from patch antenna
• antenna structures inverted-F antenna structures, closed and open slot antenna structures, loop antenna structures, monopoles, dipoles, planar inverted-F antenna structures, hybrids of these designs, etc.
• the resulting antenna structures may be incorporated into the housing of a relatively compact portable electronic component, such as described above, in which the available interior space is relatively small.
• Figs. 4-5 One particularly suitable electronic component that includes an antenna structure is shown in Figs. 4-5 is a handheld device 410 with cellular telephone capabilities. As shown in Fig. 4, the device 410 may have a housing
• a display 414 may be provided on a front surface of the device 410, such as a touch screen display.
• the device 410 may also have a speaker port 440 and other input-output ports.
• One or more buttons 438 and other user input devices may be used to gather user input.
• an antenna structure 426 is also provided on a rear surface 442 of device 4 0, although it should be understood that the antenna structure can generally be positioned at any desired location of the device.
• the antenna structure 426 may contain a planar substrate that is formed from the polymer composition of the present invention.
• the antenna structure may be electrically connected to other components within the electronic device using any of a variety of known techniques.
• the housing 412 or a part of housing 412 may serve as a conductive ground plane for the antenna structure 426.
• a planar substrate that is formed form the polymer composition of the present invention may also be employed in other applications.
• the planar substrate may be used to form a base of a compact camera module ("CCM"), which is commonly employed in wireless communication devices (e.g., cellular phone).
• CCM compact camera module
• FIGs. 6-7 for example, one particular embodiment of a compact camera module 500 is shown in more detail.
• the compact camera module 500 contains a lens assembly 504 that overlies a base 506.
• the lens assembly 504 may have any of a variety of configurations as is known in the art, and may include fixed focus-type lenses and/or auto focus-type lenses.
• the lens assembly 504 is in the form of a hollow barrel that houses lenses 604, which are in communication with an image sensor 602 positioned on the main board 508 and controlled by a circuit 601 .
• the barrel may have any of a variety of shapes, such as rectangular, cylindrical, etc.
• the barrel may also be formed from the polymer composition of the present invention and have a wall thickness within the ranges noted above. It should be understood that other parts of the camera module may also be formed from the polymer composition of the present invention.
• a polymer film 510 e.g., polyester film
• thermal insulating cap 502 may cover the lens assembly 504.
• the film 510 and/or cap 502 may also be formed from the polymer composition of the present invention.
• Yet other possible electronic components that may employ the polymer composition include, for instance, cellular telephones, laptop computers, small portable computers (e.g., ultraportable computers, netbook computers, and tablet computers), wrist-watch devices, pendant devices, headphone and earpiece devices, media players with wireless communications capabilities, handheld computers (also sometimes called personal digital assistants), remote controllers, global positioning system (GPS) devices, handheld gaming devices, battery covers, speakers, camera modules, integrated circuits (e.g., SIM cards), housings for electronic devices, electrical controls, circuit breakers, switches, power electronics, printer parts, etc.
• GPS global positioning system
• Comparative Tracking Index (CTI) The comparative tracking index
• CTI CTI rating
• two electrodes are placed on a molded test specimen.
• a voltage differential is then established between the electrodes while a 0.1 % aqueous ammonium chloride solution is dropped onto a test specimen.
• the maximum voltage at which five (5) specimens withstand the test period for 50 drops without failure is determined.
• the test voltages range from 00 to 600 V in 25 V increments.
• the numerical value of the voltage that causes failure with the application of fifty (50) drops of the electrolyte is the "comparative tracking index.”
• the value provides an indication of the relative track resistance of the material.
• An equivalent method for determining the CTI is ASTM D-3638-12.
• melt Viscosity The melt viscosity (Pa-s) may be determined in accordance with ISO Test No. 11443 at a shear rate of 1000 s " and temperature
• the rheometer orifice (die) had a diameter of 1 mm, length of 20 mm, L/D ratio of 20.1 , and an entrance angle of 180°.
• the diameter of the barrel was 9.55 mm + 0.005 mm and the length of the rod was 233.4 mm.
• Tm The melting temperature
• DSC differential scanning calorimetry
• DTUL Deflection Temperature Under Load
• test strip sample having a length of 80 mm, thickness of 10 mm, and width of 4 mm was subjected to an edgewise three-point bending test in which the specified load (maximum outer fibers stress) was 1 .8 Megapascals.
• the specimen was lowered into a silicone oil bath where the temperature is raised at 2°C per minute until it deflects 0.25 mm (0.32 mm for ISO Test No. 75-2).
• Tensile Modulus, Tensile Stress, and Tensile Elongation Tensile properties are tested according to ISO Test No. 527 (technically equivalent to ASTM D638). Modulus and strength measurements are made on the same test strip sample having a length of 80 mm, thickness of 10 mm, and width of 4 mm. The testing temperature is 23°C, and the testing speeds are 1 or 5 mm/min.
• Flexural Modulus, Flexural Stress, and Flexural Strain Flexural properties are tested according to ISO Test No. 178 (technically equivalent to ASTM D790). This test is performed on a 64 mm support span. Tests are run on the center portions of uncut ISO 3167 multi-purpose bars. The testing
• Notched Charpy Impact Strength Notched Charpy properties are tested according to ISO Test No. ISO 179-1 ) (technically equivalent to ASTM D256, Method B). This test is run using a Type A notch (0.25 mm base radius) and Type 1 specimen size (length of 80 mm, width of 10 mm, and thickness of 4 mm). Specimens are cut from the center of a multi-purpose bar using a single tooth milling machine, The testing temperature is 23°C. EXAMPLE 1
• a sample (Sample 1 ) is formed from 63.4 wt.% of a liquid crystalline polymer, 18 wt.% glass fibers, 18 wt.% talc, 0.3 wt.% GlycolubeTM P, 0.2 wt.% aluminum trihydrate, 0.1 wt.% 4,4'-biphenol, and 0.025 wt.% 2,6-naphthelene dicarboxylic acid.
• a control sample (Control Sample 1 ) is also formed from 63.7 wt.% of a liquid crystalline polymer, 18 wt.% glass fibers, 18 wt.% talc, and 0.3 wt.% GlycolubeTM P.
• the liquid crystalline polymer in each of the samples is formed from HBA, HNA, TA, BP, and APAP, such as described in U.S. Patent No. 5,508,374 to Lee, et al.
• the glass fibers are obtained from Owens Corning and have an initial length of 4 millimeters. Parts are injection molded from Sample 1 and Control Sample 1 and tested for CTI, thermal properties, and mechanical properties. The results are set forth below in Table 1
• a sample (Sample 2) is formed from 49.7 wt.% of a liquid crystalline polymer, 10 wt.% glass fibers, 15 wt.% talc, 25 wt.% titanium dioxide, 0.3 wt.% GlycolubeTM P, 0.2 wt.% aluminum trihydrate, 0.1 wt.% 4,4 -biphenol, and 0.025 wt.% 2,6-naphthelene dicarboxylic acid.
• a control sample (Control Sample 2) is also formed from 50.0 wt.% of a liquid crystalline polymer, 10 wt.% glass fibers, 15 wt.% talc, 25 wt.% titanium dioxide, and 0.3 wt.% GlycolubeTM P.
• the liquid crystalline polymer in each of the samples is formed from HBA, HNA, TA, BP, and APAP, such as described in U.S. Patent No. 5,508,374 to Lee, et al.
• the glass fibers are obtained from Owens Corning and have an initial length of 4 millimeters. Parts are injection molded from Sample 2 and Control Sample 2 and tested for CTI, thermal properties, and mechanical properties. The results are set forth below in Table 2.
• Example 3 Seven samples (Samples 3-9) are formed from various percentages of a liquid crystalline polymer, glass fibers, talc, titanium dioxide, GlycolubeTM P, aluminum trihydrate (“ATH”), 4,4'-biphenol (“BP”), and 2,6-naphthelene dicarboxylic acid (“NDA”) as set forth in Table 3 below.
• a liquid crystalline polymer glass fibers
• talc titanium dioxide
• GlycolubeTM P titanium dioxide
• GlycolubeTM P aluminum trihydrate
• BP 4,4'-biphenol
• NDA 2,6-naphthelene dicarboxylic acid
• the liquid crystalline polymer in each of the samples is formed from HBA, HNA, TA, BP, and APAP, such as described in U.S. Patent No. 5,508,374 to Lee, et al.
• the glass fibers are obtained from Owens Coming and have an initial length of 4 millimeters. Parts are injection molded from the samples and tested for CTI, thermal properties, and mechanical properties. The results are set forth below in Table 4.

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